Evaporator



Sept 7, 1943. B. c. JoHNsoN 2,328,723

EVAPORATOR I Filed Dec. 2, 1940 's sheets-sheet 2 l? 15e/Hard yC'. Jono' Sept. 7, 1943. B. c. JOHNSON 2,328,723

' v EVAPORATOR l Filed'neo. 2, 1940 s'sheets-sheet 3.

-VEZF m3er/'mrd C. Johnson (ggg. l SR1! SageWa/y.

Patented Sept. 7, 1943 UNITED STATI-:s PATENT" oFFicE EVAPORATOR Bernard C. Johnson, Libertyville, Ill., assignor to Houdalle-Hershey Corporation, Detroit, Mich.

a corporation of Michigan 1 Application December 2, 1940, Serial No. 368,187

s claims. (ci. ca -12s) This invention relates to sheet metal heat exchangers.

More specifically the invention relates to U- shaped sheet metalevaporator units-.for refrigerators which units have shelves carried by the side walls thereof and equipped with refrigerant circulating ducts for cooling articles mounted? thereon. Y

. This application is a continuation in part of my copending application entitled: Evaporaton Serial No. 279,878, led June 19, 1939, now Patent No. 2,310,906, February 9, 1943.

In the copending application above referred toY there is disclosed and claimed a U-shaped sheet metal evaporator unit formed by securing two embossed fiat sheets of metal together and bending the embossed sheets -into the shape of a. U

to provide the side walls and bottom of a sharp freezing chamber. The outer sheet of the unit is embossed with a pair of header depressions extending across each end portion thereof. Embossed refrigerantpassageways extend longitudinally of the sheet and communicate with the header depressions. A-transverse inlet passageway is embossed intermediate the ends of the longitudinal passageways in intersecting relation therewith. This transverse inlet passageway serves as a manifold to distribute refrigerant to each of the circulating passageways.

The outer sheet is also embossed with an outlet passageway communicating with the outer header depression and extending throughout the length of the sheet so that both of the top headers can be exhausted through this single pas- The inner sheet is also provided with header depressions for complementary registration with the header depressions in the outer sheet. The two sheets, when secured together, form tubular header chambers in spaced superimposed relation on each leg of the U-shaped unit. In the said application these header chambers are connected through embossed ducts formed on the outer sheet.

The present invention now relates to improvements in evaporator constructions such as arev fdisclosed in said application Serial No. 279,878.

These improvements deal with the formation of embossed flutes on'the inner sheet of .the unit for connecting the superimposed headers whereby natural bales are provided to prevent the 'splashing of unspent liquid refrigerant into the -upper header chambers:

An important feature of the present invention `is the provision of one or morerrefrigerated shelves for thev evaporator unit.'which shelves have substantially no contact withrtheV walls of the unit in order that metal coating material such as zinc can readily flow between the shelves and the unit walls, thereby eliminating a heretofore-required soft soldering-operation;

Anotherfeatureof this invention includes the provision of-upstanding legs on the refrigerant inlet and outlet tubes, which llegs serve as tray stops. Y

It is, then, an object of this invention to provide sheet metal Vevaporator units with a superimposed pair of headers connected through embossed flutes in offset relation to the embossed 'refrigerant utes of the unit.

Another object of the invention is to provide a sheet metal evaporator unit having a separate shelf fixedly mounted therein inspaced relation from `Vthe walls thereof to facilitateflowing of coating material between Vthe evaporator unit and shelf.

A specific object of the invention is to provide an improved connection between the shelf and walls of sheet metal evaporator units.

Another specific object of the invention visto provide upstanding legs'on the inlet and exhaust Vtubes connected to an evaporator unit whereby said legs can serveEH as tray stops.

A further objectof the invention is to provide a sheet metalr evaporator unit` with a refrigerated shelf maintained in spaced relation from the walls of the unit except at minute contact areas to thereby eliminate the necessity for soldering or welding the shelf to the evaporator walls.

Other and further objects of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which disclose preferred embodiments of the invention.

On the drawings:

Figure 1 is a top-plan view of a sheet metal evaporator unit'with a refrigerated shelf according to this invention.

Figure 2 is a side elevational view of the evaporator unit shown in Figure 1. o

Figure 3 is a rear end elevational View of the evaporator unit shown in Figures l and 2.

Figure 4 is an enlarged broken horizontal cross sectional view taken along the line IV-IV of Figure 3.

Figure 5 is a fui ther enlarged cross-sectional detail view illustrating the manner in which coating material can readily flow between the shelves and side walls of an evaporator unit according to this invention.

Figure 6 is an. enlarged vertical cross-sectional view taken along the line VIV-VI of Figure 2.

Figure 7 is an enlarged fragmentary horizontal view taken along the lineVII-VII of Figure 2.

Figure 8 is a rear end elevational view of an evaporator unit according to this invention having two superimposed refrigerated shelves.

Figure 9 is a vertical cross-sectional view taken along the line IX-IX of Figure 8. 2

Figure 10 is a fragmentary cross-sectional view along the line X-X of Figure 9.

As shown on the drawings: f

'In Figures 1 to 3 inclusive the reference numeral Illl designates generally an evaporator unit composed of an inner metal sheet II and an outer metal sheet I2. The sheets II and I2 are secured together by brazing, spot-welding, stitchwelding or the like. 'I'he evaporator unit I0 is U-shaped, as best shown` in Figure 3, to denne spaced vertical side walls I3 and a bottom |4 of a sharp freezing chamber I5.

The top ends of the side walls I3 can be bent horizontally inward to provide flanges I6 which may be apertured as at I'I (Fig. 1)v for receiving suspension means to hang the unit in a refrigerator cabinet, preferably from the top Wall of the cabinet. .o y

The outer sheet I2 has semi-cylindrical flutes I8 and I9 embossed therein near the upper end thereof as shown in Figures 2 and 3. The inner sheet I l has complementary semicylindrical embossed flutes I8a and IBa forming, with the flutes on 'the outer sheet, a pair of superimposed header chambers 20 and 2| on each side wall I3 of the unit at the upper ends of the side Walls.

The outer sheet I2, as shown in Figures 2 and ship between the passageways 22 and 2li as well as between the passageways 22 and 25' hinders the ow of unspent refrigerant to the top header chambers ZIJ while the gasified or spent refrigerant can freely pass into the upper header.

The gasified or spent refrigerant isremoved from the upper header chamber 20 through an embossed flute 26 on the outer sheet I2. The flute 26 extends around the side and bottom walls of the unit and communicates with a flute 21 embossed on the inner sheet II as shown in Figures 3 and 10. The outlet passageway provided by the :flute 26 communicates with the rear ends of the top header chambers as shown in Figure 2.

A shelf 30 composed of a at top plate 3| and flanges 34 spaced inwardly from the sheet II of the unit. Each flange has two small localized outwardly embossed protuberances 35 which l slope into substantially point contact with the inner sheet II. A.rivet 36 passes through'each protuberance 35 and through the sidexwalls I3 v made from sheet steel it is desirable to zinc dip 3, has embossed flutes 22 extending around the,

` unit and communicating with the lower headers 2|.

A transverse ute 23 is embossed in the outer sheet I2 and extends longitudinally along the `bcttom I4 of the unit in communication with each of the flutes 22. Refrigerant is introduced into the flute 2 3, flows therefrom through the refrigerant distributing passageways provided bw the flutes 22 around the bottom and side walls of theunit into the lower header chambers 2|.

- the entire unit thus forming a zinc coating thereon. Heretofore the evaporator shelf always had an extensive area contact with the walls of4 the unit and the coating material could not strike down between the contacting areas. As a result itwas necessary to soft solder around the peripheral portions of each contacting area for Sealing off the contacting area. These soldering operations were time-consuming and expensive.

In accordance with this invention, as shown in Figure 5, however, the space 3`| between the shelf and the evaporator unit now makes it possible for a zinc coating 38 to flow between the shelf and side walls of the unit and form its own protecting llet 38a around any minute contacting area between the shelf and unit.

The rear end of the shelf 30 has an upstanding tube 40 soldered thereon in communication AS best shown in Figures 2, 3, '6, and '1, the 1nner sheet II is further embossed'as at 24 and 25 on each side wall I3 thereof to provide passageways connecting the header chambers 20 and 2| on each side wall. f

As best shown in Figure 6, refrigerant R entering the lower header chamber such as 2| from the distributing utes 22 may assume the indicated 1evel.\ As refrigerant gases pass through the liquid. refrigerant from the distributing ducts 22 slugs S of, liquid or unspent refrgerantwill be thrown against the uppel` portion of the embossed depression I9 on the outer sheet and cannot pass directly through the passageway provided by the embossed duct 24 to the upper header chamber 20. As a result, the oiset relation- `ceives a tube 42 extending downwardly at the rear side'of the unit to the inlet flute 23. The

refrigerant first ows through the shelf duct 33 and thence around the rear end of the unit into .the inlet duct 23 where it 21's distributed to the circulating passageways provided by the nubes 22. l

The embossed flute 21 on the bottom I4 of\ thereof receiving 'a connecting tube the unit receives an upstanding outlet tube 43 at the Vcentral portion thereof.V As shown in Figure 2, the tube 43 extends vertically upward and then slopes out beyond the rear end of the unit.

The inlet tube 40 and the outlet tube 43 have their free ends closed .by means of caps 44 to prevent entrance of foreign material into the passageways of the unit. These capsare of course removed when the unit is installed in a refrigerating system.

The upstanding legs of the tubes 4D and 4l provide stops for ice trays T mounted on the shelf 30 as shown` in dotted lines in Figure 2. Likewise the embossedute 21 and the vertically upstanding portion of the tube :43 forms a stop for ice trays such as T mounted on the.

bottom of the unit.

In the modification shown in Figures 8 and 9,V

the evaporator unit 10a is constructed the same as the evaporator I0 but has higher side Walls i3d than the evaporator l0. The same type of refrigerant distributing ducts, Yheaders and connecting conduits are used. Two shelves 30al and 30h are provided bridging the: space betweenj the side walls I3a in spaced superimposed relation.

The shelves 30a an 30h have downturned side of the tubes 40a, 40h, and 43 serve' as stops for ice trays T mounted on the top of the ,shelves a and 30h and on top of the bottom i4 of t. 3- unit.

From the above d"scriptions it should be understood that this invention now provides impr ments in sheet metal evaporator ,units whi i. have natural baiiles for retardingiiow of refrigerant into the outlet passageway from ehe unit. The units of this invention also utilize upstanding refrigerant tubes on the shelves bottoms for ice tray stops thereby avoiding heretoforer2fll1ired additionalparts.

An important feature of the units of this inu vention is therspacing of the shelves from the side walls of theunit so that heretofore-'required Ysoldering operations are eliminated and'coating material will readily strike down between the Yshelves and walls of the units.

It will; of course, be understood that various details of construction may .be varied through a wide range without departing from the principles of this invention and itgis, therefore, not the purpose to Vlimit the -patent granted hereon cthflanges 34aand 3417 respectively secured to the i side walls i3d of the unit in the same manner-as the iianges 34 are secured to the side walls of the unit by means of the rivets 36; The outturned collars a and 35h hold the flangesin spaced relation from the side Walls.

The shelves 30a.A and 30h have serpentine refrigerant passageways 33a and 33h provided therein. An L-shaped inletv vertical leg., thereof soldered to the shelf 30a communicating with the passageway 33a. Refrigerant is introduced through'A the tube 40o and flows through the passageway 33a to a second L-shaped tube 4|a having the vertical leg communicating with the other end of the passageway 33a and having the' `horizontal leg 42a. The connecting tube 42a extends around .the rear pipe 40a has the' erwise ,than necessitated by the lscope of the appended claims. l

I claim as my invention:

1. A sheet metal evaporator unit having a bote tom and side walls with a pair of superimposed Cil end of the shelf 30a to the horizontal legV of a second-L-shaped tube 4|b. .The vertical leg`-of the tube 4`Ib is soldered`to the .shelf 30h and communicates with thev passageway 33h. A` `fourth L-shaped tube 40ib is soldered to the shelf 30h at the outlet end of the kpassageway 33h and receives a tube 42h cornrn'micatingy with the inlet flute 23a, of the unit.V The' `suction tube or outlet tube 43 isthe sameas the outlet tube 43 for the unitll and is in communication with the outlet duct 21 of the unit.

it win be notedithaothe inlet manifold flute 23a, is in offset rel-ation from the central portion of the bottoni of the unit lua, whereas in the center of the bottom of the unit.

The refrigerant is introduced into the tube 40a, flows through the shelf passageway 33a,

thence out of the tube lla through the tube 42a i into the tube 4Ib. From the tube 4Ib it ows ingleg portions of thetubes header chambers in each side wall, refrigerantl circulating utes on one face of the unit connecting the lower headerchambers, flutes on the opposite face of the unit connecting the header chambers of each pair whereby the passageways defined by the refrigerant circulating flutes are in offset relation from the passageways defined by the utes connecting the header` chambers of each pair, a shelf bridging the side walls above the bottom of the unit, localized lateral projections spacing the shelf from the side walls, refrigerant circulating flutes on the shelf, a re' frigerant inlet tube secured to said shelf and having an upstanding leg portion at `the rear end of the shelf, a refrigerant outlet tube having an upturned leg portion secured on said shelf and joining the shelf flutes with therefrigerant circulating flutes of the unit, a suction flute embossed on the unit connecting the top chambers of said pairs, and a single suction tube communicating with said embossed flute and having a leg portion extending upwardly from the bottom of the unit at the rear end thereof, said upstandbeing arranged to act as tray stops. i

2. A sheet-metal evaporator unit comprising a pair of secured-together contiguous metal sheets defining the side walls and bottom of a sharp freezing chamber, said sheets being embossed to elapmrator unit m the inlet flute 23 is-at theo deneapalr of superimposed header chambers 1n eachside wall, one of Said sheets being further embossed to define refrigerant circulating ducts connecting the lower header chambers of said pairs, the other of said sheets being embossed to define passageways connecting the headers of each pair, said ducts and passageways being in offset relation to retard flow of unspent refrigerant into the top header chamber, a shelf bridging the side walls of the unit in spaced relation from the bottom thereof having localized laterally extending projections in restricted contact with the said side walls for holding the .shelf in spaced relation from the unit, and refrigerant inlet and outlet tubes secured to said portions shelf having upstanding leg portions adapted to 'connecting the upper .and lower header chambers of each pair, a pair of secured-together contiguous metal sheets having flanges at the longitudinal sides thereof and together dening a shelf for the unit, one of said shelfdefining sheets being embossed tov form a refrigerant duct having the ends thereof adjacent the rear edge of the sheet, upstanding tubes secured to the bossed'portions for uniting the shelf with the side Walls, and coating material covering the side walls and flanges to protect the same against corrosion. i

6. A sheet metal evaporator unit comprising a pair of secured-together contiguous metal sheets defining the'side Walls and bottom of a sharp freezing chamber, said sheets` being embossed to dene a pair of superimposed header chambers in each side wall, one of said sheets being. embossed to define a pluralityof refrigerant circulating ducts connecting the lower header chambers vof said pairs, at least one ofV said-sheets being further embossed to dene a passageway joining the top header chambers of said pairs,

. a single exhaust tube communicating with said top shelf defining sheet in communication with the ends of said duct, apertured protuberances projecting from said flanges, rivets extending through said protuberances securing the plates to the side walls of thev unit in spaced relation from the bottom thereof, and a tube connecting one of said upstanding tubes with said refrigerant circulating ducts to place said one upstanding tube in fluid flow communication with said circulating ductsI whereby refrigerant can beintroduced into the other of said upstanding tubes for flowing through theduct in-the shelf to the other of said upstanding tubes and thence through the connecting tube to the refrigerant.

circulating ducts and said upstanding tubes being arranged to serve as tray stops.

4. A sheet metal evaporator unit comprising a pair of secured-together contiguous metal sheets dening theside walls and'bottom of a sharp freezing chamber, said sheets being embossed to define a pair of superimposed header chambers in each side wall, one of said sheets being further embossed to define refrigerant circulating ducts connecting the lower header chambers of said pairs, and the other of said sheets being embossed to define passageways connectt ing the top and bottom header chambers of each pair, said ducts and said passageways being in oiset relation to retard flow of unspent refrigerant from the ducts to the top header chambers.

5. A heat absorber comprising sheet metal delining spaced opposed side walls,V a shelf bridging said side walls having turned-down flanges in spaced parallel relation from the side walls, apertured laterally projecting embossed portions on said flanges in rim engagement only with said sidelwalls, securing means extending through the sidewalls and through the apertures of the empassageway, a shelf Spanning the side walls of said unit in spaced relation from the bottom thereof, a refrigerant duct formed under said shelf, an inlet tube for supplying refrigerant to said duct, and an outlet tube connecting said duct with the .refrigerant circulating ducts in said unit whereby a single inlet and a single outlet provide for the circulation of refrigerant through the shelf and through the unit.

7. In an evaporator unit including a pair of" secured-together contiguous metal sheets defining the side walls and bottom of a sharp freezing chamber, said sheets being embossed to dene a header chamber in each side Wall, the outer of said sheets being further embossed to define a passageway connecting the header chamber in one side Wall with the header chamber in thev other side wall, the inner of said sheets being embossed along the bottom of the unit to form a rib across the rear end of the unit adaptedto act as a stop for articles mounted on the bottomy of the unit and said rib defining a passage in communication with said passageway.

8. The method of protecting against corrosionv an evaporator unit ofthe type having a shelf spanning side walls of the unitV and carried by said side walls which comprises forming flanges on the longitudinal Side edges of the shelf in spaced relation from the side walls of the evapo-V rator unit, embossing localized laterally extending Aprojections atY materially spaced intervals along said flanges, bending said embossed portions into sloping rim edge engagement with the side Walls to maintain the flanges in spaced relation from the side walls while contacting said side wallsonly at the rim edges of the embossed portions, securing the embossed portions to the` side walls, and coating the assembly to cause the coating material to strike down between the flanges and side walls of the unit.

BERNARD C. JOHNSON. 

